Cherry red spots on the macula
Introduction
Introduction Niemann-Pick's disease (NPD) is an inherited metabolic disease caused by sphingomyelin and cholesterol deposits in various organs of the body. It is often seen in young children. It has liver and spleen and yellow-spotted cherry. Main features such as large foam-like cells in red spots and bone marrow smears. The disease was first reported by Niemann in the first case in 1914. In 1922, Pick described the pathological findings in detail, hence the name. For the first time, China reported 2 cases in 1963, and there have been reports in the following.
Cause
Cause
The cause of cherry red spots in the macula of the fundus: autosomal recessive inheritance.
Pathophysiology:
The disease is autosomal recessive, and Jewish people are more ill. It has been confirmed that the type A and type B of this disease are caused by the lack of sphingomyelinase. The enzyme is widely present in lysosomes of various tissue cells, and is also found in mitochondria and microsomes, especially in hepatocytes. Sphingomyelin is present in the plasma membrane of all cell membranes and subcellular membranes, including the matrix of red blood cells. When the enzyme is deficient, such lipids cannot be hydrolyzed, resulting in a large accumulation in the cells, often accompanied by deposition of cholesterol and bisphosphonate. The principle of increased cholesterol is unclear. There seems to be a close relationship between cholesterol and sphingomyelin metabolism, and there may be a small increase in other sphingolipids. In the cells of type C and type D, the main deposits are cholesterol, sphingomyelin is less, and sphingomyelinase is also decreased in cells, and the levels are between A and B and normal people. There are obvious obstacles in the esterification of exogenous cholesterol in patients' skin fibroblasts, and based on this possible pathogenesis, homozygotes, carriers and prenatal diagnostic methods have been established, so this is considered to be Type of cause of the disease. The gene for sphingomyelinase is located on chromosome 17, and its structure is well understood. The type C gene is mutated on chromosome 18.
Examine
an examination
Related inspection
Ophthalmologic examination fundus examination slit lamp
Examination of the red spot of the yellow spot on the fundus:
Symptoms and signs:
1. Type A: 3 to 4 months after birth, feeding difficulties, malnutrition, liver and spleen, often appear before the splenomegaly, lymph node enlargement, mental nerve development retardation, but because of its progress It is slower, so it is often not found within a few months after the disease. Not only does it fail to meet the developmental standards of that age, but it also shows regression and muscle strength is also reduced. The skin has a brown pigmentation, and the lungs can be affected. In severe cases, both hearing and vision are affected or even lost. 30% to 50% of patients have cherry red spots on the macula of the fundus. The child gradually loses weight, often died of secondary infection before the age of 3 to 4.
2. Type B: This type progresses very slowly. Except for the liver and spleen, there is no or only mild nervous system performance, which can lead to long-term survival.
3. Types C and D: The child has normal performance within a few years after birth, and gradually develops neurological symptoms such as vocabulary reduction, ataxia, convulsions, and supranuclear ocular paralysis. The liver is big and the spleen is not as big as the liver. The disease progresses slowly, the mental and motor development gradually declines, and later the muscle tension increases, and the hyperreflexia occurs. Types C and D perform similarly, but Type C is commonly found in Nova Scotia, Canada. Some unexplained neonatal hepatitis was found to be a type C patient.
Diagnostic check:
Diagnosis: Infants and young children have liver and spleen, and the liver is larger than the spleen, and the nervous system appears gradually. The disease should be suspected. If there is a cherry red spot in the macular area, there are miliary changes in the lung X-ray film. The diagnosis of this disease, the important diagnosis is based on the discovery of typical foam-like Niemann-Pick cells in the bone marrow. Determination of sphingomyelinase activity can be confirmed if reduced.
Laboratory inspection:
1. Blood: There may be moderate anemia, thrombocytopenia, the extent of which depends on the extent of bone marrow involvement. Leukocytes are generally normal, can be reduced or even slightly increased, lymphocytes and monocytes can have vacuoles.
2. Bone marrow: The degree of myeloproliferation and the proportion of various cells are normal. Typical Niemann-Pick cells can be found. The diameter of the cells is 20-90 m, round, elliptical or angular, with a small eccentricity. The nucleus is filled with foamy sphingomyelin granules like mulberry-like fat droplets. This structure makes the cytoplasm foamy, so it is also called foam cells. The Ritter staining was light blue, the lipid (Sudan III) staining was positive, the glycogen staining vacuolar wall was positive, the vacuolar center was negative, and the alkaline phosphatase and peroxidase staining were negative.
Other auxiliary inspections:
1. X-ray examination: type A can have miliary infiltration in the lungs, bone can have mild medullary cavity enlargement and cortical thinning, brain CT and MRI examination can have gray matter degeneration, demyelinating lesions and cerebellar atrophy.
2. Enzyme assay: Leukocyte, skin biopsy examination fibroblast culture assay to reduce sphingomyelinase.
3. Others: Skin fibroblast culture detects cholesterol esterification, has a disorder in type C, and is also stained with filipin, which shows accumulation of unesterified cholesterol in lysosomes. Rectal biopsy clearly shows deposition in C-type nerve cells before (some sometimes several years) the appearance of neurological symptoms.
Infection is a common complication and a major cause of death and should be treated aggressively.
Diagnosis
Differential diagnosis
The red spots on the macula of the fundus are easily confused.
The macula was found to have gray discoloration at the fundus: Austin-type children with cerebral sulfatosis, also known as Austin-type metachromatic leukodystrophy, is a joint disease of cerebral sulphur disease and mucopolysaccharidosis. It is characterized by mild Hurler syndrome, multiple bone dysplasia, severe neurological symptoms and markedly low intelligence. Under the fundus examination, it can be found that the macula is grayish and discolored, and even blind.
Fundus cherry erythema: due to the interruption of the fundus arterial blood supply, diffuse gray-white edema in the posterior pole of the retina, the fovea in the fundus, and the striking "cherry erythema" in the surrounding gray-white edema area.
Spotted or flaming hemorrhage in the fundus: Fundus hemorrhage is not an independent eye disease, but a feature common to many eye diseases and certain systemic diseases. Common in retinopathy caused by hypertensive retinopathy, diabetes and kidney disease. Retinal vein inflammation, retinal vein occlusion, optic disc vasculitis, and blood diseases cause retinopathy, ocular traumatic fundus hemorrhage. The same pathological damage, such as retinal hemorrhage, exudation, microangioma, neovascularization, etc., due to various causes.
